Ju Guohao, Ma Hongcai, Yan Changxiang
Opt Express. 2018 Sep 17;26(19):24816-24834. doi: 10.1364/OE.26.024816.
Due to the absence of rotational symmetry, off-axis astronomical telescopes with off-set pupil become subject to rotational misalignments. Rotational misalignments of large off-axis mirrors with reference to their geometric center can greatly degrade the imaging quality. This paper presents an in-depth discussion on the net aberration fields of off-axis astronomical telescopes induced by rotational misalignments. Aberration function of off-axis telescopes with rotational misalignments is derived based on the framework of nodal aberration theory. Expressions of several important aberrations are obtained under some approximations. Then the specific field characteristics of these aberrations are presented and explicated. Meanwhile, we demonstrate that rotational misalignments can be converted to a kind of surface decenters; on the other hand, the effects of rotational misalignments have their special features which are different from the effects of general surface decenters. Besides, some other insightful discussions are further presented. This work is also applicable to the rotational misalignments of the off-axis segments of primary mirror in segmented mirror astronomical telescopes.
由于缺乏旋转对称性，具有偏心光瞳的离轴天文望远镜容易出现旋转失准。大型离轴镜相对于其几何中心的旋转失准会极大地降低成像质量。本文深入讨论了由旋转失准引起的离轴天文望远镜的净像差场。基于节点像差理论框架推导了具有旋转失准的离轴望远镜的像差函数。在一些近似条件下得到了几种重要像差的表达式。然后给出并阐述了这些像差的具体场特征。同时，我们证明旋转失准可以转换为一种表面偏心；另一方面，旋转失准的影响具有与一般表面偏心影响不同的特殊特征。此外，还进一步给出了一些有见地的讨论。这项工作也适用于拼接镜面天文望远镜中主镜离轴部分的旋转失准。
